Steam-engine.



` J. STUMPF. STEAM ENGINE.

APPLIAION FILED JULY 26,1916@ Patented lJun@ 4, 1912.

2 SHEETS-SHEET Z.

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JOHANN s'rUMr-r, or BERLIN. GERMANY.

STEAM-NGINE.

Application filed July 2.6,1910. Serial No. 573,933.

trolled by` thel piston in its motion. The invention is specially directed to engines of I this type which are required for maneuver- -ing purposes, such as Winding engines which require to be stopped dead and accurately in some required position. In uni-directional ioW steam engines with compression extending over 90% of the return stroke, such ac-. curate and dead-'smpping is difficult. The admission steam on one side of the piston and the highly compressed residual steamv on the other side cause an oscillating movenient of the piston vwhich, in a Winding engine, would in`\- turn cause an oscillating movement ot the Winding drum andl probably 'lead to accidents.

The object of the-present invention is to provide maneuvering gear for uni-directional ioyv steam engines Which will .enable them to be stopped dead and "accurately in any required position.

The invention consists in a uni-directional tiow steam engine having in addition' and supplementary exhaustvalves, the gear4 to the usual piston-controlled exhaust ports further exhaust ports controlled bymembers which are only operated when the out o is late and which retain thcadditional exhaust ports closed during normal or early out oi.

The 'method of carrying out this invention conveniently adopted consists in employing variable cam gear for 'operatingl the inlet being such that' the supplementary exhaust valves remain closed and Aunoperated during normal or earlyv out off and are only affected when thel cut ed is late; for operating the' supplementary exhaust valves are preferably articulated to the inlet, valve cams so as to be adjusted `simultaneously and interdependently therewith.

1With this invention, the engine operates with maximum eiiiciency as an ordinary-.-

- uni-directional flow steam engine during thel Specification of Letters Pat-ent.

The cams l .Patentedaune4, 1.9.12.

greater part of its working time and the supplementary exhaust valve` gear lis only called into action When maneuvering, that is when the inlet valves are raised a short distance and for a longertime than in ordinary running The necessaryV tlirottling formaneuvering can thus be eiected by altering the cam gear Without affecting the engine throttle valve.- Also the adjustment vof the inlet valve gear for starting also ai'ects'the supplementary exhaustA so that it comes-into operation to'assist starting.

The variable cam gear employed consists. convenientlyv of suitable conical cams -mounted on a sliding sleeve and all the val-ves bot-h inletand supplen'ientary exhaust aft. `The invention is illustrated by way ot example inthe accompanymg dra-Wings which 'foKA are preferably operated from a single Cam illustrate part .of a' doubleacting uni-dircetionalilow steam engine.

In .these ldrawings: Figure 1 is a vertical sectional elevatlon ot ahorlzontal engine' cylinder. Fig. 2 is a plan ofA the cylinderk shownin'Fig. l. i

In carrying the invention into effect ac.-

cording to thel form shown the cylinderl a 'is supplied. with Working steam through valves b at jthe admission endsv of the cylinders. The ordinary exhaust takes place --through ports c controlled by the piston in its motion, which ports open i'ntoan annular chamber d. Thesupplementary exhaustvalves e according toth'is-invention control the ports 7 which vcommunicate with the cylinders at or near the admission ends. Thel 'portsor passages f are continued behind the valve e inthe passages f1- which'communicate Awith the annular chamber ZI` 'The inlet valves b. andthe supplementary or maneuvering exhaust valves e areoperated from a common' cam' shaft g, which. in the form shown is'rotatable. On the shaft-g thereare arranged 4the cams l2. and 7i: for thecinlet and supplementary exhaust valves respectively. These cams are suitablyartioul'ated. Inthe .form shoWn they are .both formed or mounted von' one sleeve so that their adjustment is simultaneous and interdependent. The' arrangement and shape/of they cams Will be evident from lthe above description.

, Any suitablefgear 'may be'used for sliding I or otherwiseV adjusting the cams'. On thel ams there bear'rollers and s which operate '110 y the valvesand e through any Well k-novvii lift .ofV lon duration for; either direction of. rotation o ythe engine, the cones 7c are also 4form of intermediate links and levers o and l p respectively.'

h whichare shown as 'double If the lcams cones, are set to give the-'inlet valves-a small "set to open the vvalves effor e convenient time to allovvfrthe residual steam'to 'escape' in the desiredainount through the passages 'f. When theycut'o is made sooner the openingvor period of opening of the valves e is reduced till 'when the cut off is .normal said inlet port-5 means for operating said inlet valve said lmeans being adjustable to give .i earlier or later cut offof the valve as required, a supplementary .exhaust passage 'communicating- With the inlet end oi said cylindera .valve normally at rest and clos ing said supplementary exhaust passage and means vfor moving said valve from its nor` mal position' of, restv to relieve compression when the out oif 1s late comprising a member -movable and adjustable With'the operating means for the admission 'valve and an operating member fori-the supplementary 4exl haus't valve arranged to eo-act with said- -movable member to operate said supplementary exhaust valve When tliepoperating means for the admission valve gives late cut o;

2. In combination with a cylinder having a steam inletport at its end and a main exhaust port, an admission valve. 'COntrolling the admission of steam to said cylinder through said inlet port, a slidable and lrotatable cam for operating said valve to give a variable cut ed as desired7 a supplementary exhaust passage communicating with the inlet end of the cylinder, a valve normally .at

Arest and closing said supplementaryexhaust passage and means for movingrsaid valve' trom lts normal' position of rest torelieve compression when the clit 0E is late-comprising a cam slidable and' rotatable with the 'operating `cam for themdmission" valve and an operating arm' for'jsad supplementary exhaust valve, saidoperatingarm being arl .'55,-

ranged to yco-act effectively withy said; rotatable and slidable .camwl'ienthe operating means'for the admission valve is located to give a late cut o i. .In 4Witness whereof inyhand inthe presence of two-witnesses, :Josemi s'ruMPr Witnesses: 't

JOHANNES HEYNEMANN, FRANZ l I have hereunto set". 

